[Sema] Fix bug in builtin AS override (#138141)

Fix the logic in rewriteBuiltinFunctionDecl to work when the builtin
has a pointer parameter with an address space and one without a fixed
address space. A builtin fitting these criteria was recently added.
Change the attribute string to perform type checking on it, so without
the sema change compilation would fail with a wrong number of arguments
error.

Author: Sisyph

clang/include/clang/Basic/BuiltinsAMDGPU.def

@@ -257,7 +257,7 @@ TARGET_BUILTIN(__builtin_amdgcn_flat_atomic_fadd_v2bf16, "V2sV2s*0V2s", "t", "at
 TARGET_BUILTIN(__builtin_amdgcn_global_atomic_fadd_v2bf16, "V2sV2s*1V2s", "t", "atomic-global-pk-add-bf16-inst")
 TARGET_BUILTIN(__builtin_amdgcn_ds_atomic_fadd_v2bf16, "V2sV2s*3V2s", "t", "atomic-ds-pk-add-16-insts")
 TARGET_BUILTIN(__builtin_amdgcn_ds_atomic_fadd_v2f16, "V2hV2h*3V2h", "t", "atomic-ds-pk-add-16-insts")
-TARGET_BUILTIN(__builtin_amdgcn_load_to_lds, "vv*v*3IUiIiIUi", "t", "vmem-to-lds-load-insts")
+TARGET_BUILTIN(__builtin_amdgcn_load_to_lds, "vv*v*3IUiIiIUi", "", "vmem-to-lds-load-insts")
 TARGET_BUILTIN(__builtin_amdgcn_global_load_lds, "vv*1v*3IUiIiIUi", "t", "vmem-to-lds-load-insts")
 
 //===----------------------------------------------------------------------===//

clang/lib/Sema/SemaExpr.cpp

@@ -6395,7 +6395,8 @@ static FunctionDecl *rewriteBuiltinFunctionDecl(Sema *Sema, ASTContext &Context,
       return nullptr;
     Expr *Arg = ArgRes.get();
     QualType ArgType = Arg->getType();
-    if (!ParamType->isPointerType() || ParamType.hasAddressSpace() ||
+    if (!ParamType->isPointerType() ||
+        ParamType->getPointeeType().hasAddressSpace() ||
         !ArgType->isPointerType() ||
         !ArgType->getPointeeType().hasAddressSpace() ||
         isPtrSizeAddressSpace(ArgType->getPointeeType().getAddressSpace())) {
@@ -6404,9 +6405,6 @@ static FunctionDecl *rewriteBuiltinFunctionDecl(Sema *Sema, ASTContext &Context,
     }
 
     QualType PointeeType = ParamType->getPointeeType();
-    if (PointeeType.hasAddressSpace())
-      continue;
-
     NeedsNewDecl = true;
     LangAS AS = ArgType->getPointeeType().getAddressSpace();